1. Field of the Invention
The subject invention relates to chlorinator apparatus and, particularly, to an improved chlorinator apparatus employing electrolysis of salt and suitable for providing chlorine gas in quantities sufficient for disinfecting residential swimming pools
2. Description of Related Art
The basic theory of operation for producing chlorine from salt is very old. This process is commonly known as electrolysis, and thus chlorine generators of this type are most often classified and referred to as "electrolic or electrolytic chlorine generators."
Salt is composed of 62% chlorine and 38% sodium. The chlorine can be separated from the salt utilizing the electrolysis process. The process requires two electrodes. One electrode is called an "anode" and is connected to a positive DC electric potential. The other electrode is called a "cathode" and is connected to the negative DC electric potential. This results in a DC electrical current path from the negative cathode to the positive anode.
In order to produce chlorine gas during the electrolysis process, the electrodes are typically placed in adjacent solutions separated by a semipermeable membrane. One of these solutions is a saturated solution of salt. The other solution is tap water, which will become sodium hypochlorite during the process. When a DC electrical potential is placed across the anode and cathode, an electric current begins to flow from the cathode through the membrane to the anode. In only a few seconds, tiny bubbles of chlorine gas begin forming.
In a salt water solution, the chlorine atom has a negative charge as a result of an excess of electrons. The positive potential on the anode attracts the chlorine atoms to it. As they collect, they form tiny bubbles and rise to the surface, releasing chlorine gas. The sodium atoms left in the salt solution have a shortage of electrons and therefore are positively charged. The negative potential on the cathode attracts the positive charged sodium atoms through the semipermeable membrane. Sodium reacts with the water to form sodium hypochlorite and hydrogen. When the potential across the electrodes is increased, the reaction increases. When the potential is removed from the electrodes, the reaction stops. The membrane prevents the two solutions from contacting each other. When the DC potential is reapplied, the reaction resumes.
Chlorinators employing electrolysis of salt (NaCl) to produce chlorine gas have been in existence for some time. However, various problems have existed with their operation and maintenance. The structure of some units requires complete draining and disassembly for repair, making service relatively costly and time consuming. Any effort to remedy such problems must still ensure that current flow is not diminished, prohibiting chlorine formation, that waste materials do not collect in various areas and impede chlorine formation, and that clogging does not occur as salt dissolves. Proper flow of chlorine gas must also be controlled to prevent dangerous situations. In some units chlorine gas can accumulate in the unit or be released to the atmosphere surrounding the unit.